Food is one of the joys of traveling to Japan.
Japan is a country where you can enjoy many genres of food, from high-class cuisine to B-grade gourmet (a term Japanese use to refer to cheap and delicious food), but I would like to introduce Japanese Fast Food.
When you hear Fast Food, you likely envision things like hamburgers and hot dogs that can be eaten quickly and easily. Of course, such meals are also popular in Japan, and can be found throughout the country.

But since you have come all the way to Japan, there are more Japanese kinds of fast food I would like you to try. Namely, soba and udon.
Both soba and udon have restaurants ranging from high-class venues to chain stores, but I would especially like you to try venues that emphasize speed of service, such as “standing dining” soba and udon restaurants.

After you place your order, your food will be serviced shockingly fast- sometimes almost simultaneous to your placing the order. (Really.) Its so fast it might make you unintentionally laugh.
By the way, the soup flavoring for udon and soba is different in Kansai and Kanto. If you intend to visit Japan for a long time, it could be interesting to compare the tastes.
You might think, why waste a precious opportunity to have a meal on vacation with a dish that is eaten so quickly? But, if you think of it as experiencing the dining culture of restaurants popular with the common people of Japan, isn’t it a meaningful experience?
Also, since its pretty cheap, you can feel free to spend your leftover money at another shop for dessert.
Of course, its also perfect for when you find yourself out of time after too much sightseeing.
I hope the taste is to your liking.